<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div>
        <div>1</div>
        <div>2</div>
    </div>
</body>

<style>
    body{
        margin: 0;
    }

    #box{
        display: flex;
    }

    #box div{
        width: 6.96rem;
        height: 3.6rem;
        background: red;
        margin: 0 0.2rem;
        font-size: .64rem;
    }
</style>
</html>